Laser ignited detonators or actuators are used instead of electrical explosive devices in certain environments where electrical explosive devices are not practical including environments which are subject to appreciable amounts of electromagnetic radiation.
In certain prior art laser detonators, an optical fiber is placed up against or inside an energetic material such as a pyrotechnic material, an explosive material, or a thermite material. When the laser fires, the energetic material burns or detonates thus triggering rocket fuel, or some other explosive such as explosives used in military, mining, or construction operations.
One problem with this design includes the lack of a seal between the optical fiber and the energetic material. Thus, when the energetic material ignites, there is a hole through which fluid and/or gas can escape. Accordingly, these types of devices are unsatisfactory for rocket motors and also for missiles launched out of submarines. Another problem with such detonators is their fragile nature due to the optical fiber extending from the energetic material. Further, such actuators are not re-usable.
Other prior designs include a thin window or a ball lens between the optical fiber and the energetic material. Again, such designs do not provide an adequate seal. A thick window which could withstand the high pressure environment during device function cannot be used because a thick window is not energy efficient, and allows the laser input to diverge failing to achieve the power/energy density required to cause ignition.